1. Field of the Invention
The present invention relates to a solid-state image pickup apparatus such as a digital camera. Priority is claimed on Japanese Patent Application No. 2008-156484, filed Jun. 16, 2008, the content of which is incorporated herein by reference.
2. Description of Related Art
In the past, solid-state image pickup apparatuses are proposed using various image pickup devices such as a MOS image pickup device and a CCD image pickup device, and have been put to practical use. In addition, as an example of the solid-state image pickup apparatus provided with the MOS image pickup device, there is an amplification type solid-state image pickup apparatus which is configured such that an amplification type solid-state image pickup device (for example, an Active Pixel Sensor (APS)) having driving transistors for amplification is provided in a pixel signal generating apparatus generating pixel signals according to signal charges generated by a charge generating apparatus. Most (C)MOS solid-state image pickup apparatuses are configured as describe above.
In addition, a column ADC type solid-state image pickup apparatus which is configured to build an A/D conversion (analog-digital conversion) function in a column unit is also developed and commercialized. As a scheme of the A/D conversion, a successive-approximation A/D converting scheme, a single slope A/D converting scheme, and a cyclic A/D converting scheme are known. Further, the column ADC (A/D Converter) type solid-state apparatus which is configured to build a Time to Digital Converter (TDC, a time-digital converter) having a function of “voltage-frequency conversion” according to a signal from a pixel in the column unit is known (for example, refer to JP-A-2006-270293). JP-A-2006-270293 discloses that a signal from the pixel can be easily converted from analogue to digital with a high S/N ratio using a TDC.